Re: [libvirt PATCH v2 10/15] xen: explicitly set hostdev driver.type at runtime, not in postparse

Xen only supports a single type of PCI hostdev assignment, so it is superfluous to have <driver name='xen'/> peppered throughout the config. It *is* necessary to have the driver type explicitly set in the hosdev object before calling into the hypervisor-agnostic "hostdev manager" though (otherwise the hostdev manager doesn't know whether it should do Xen-specific setup, or VFIO-specific setup). Historically, the Xen driver has checked for "default" driver type (i.e. not set in the XML), and set it to "xen', during the XML postparse, thus guaranteeing that it will be set by the time the object is sent to the hostdev manager at runtime, but also setting it so early that a simple round-trip of parse-format results in the XML always containing an explicit <driver name='xen'/>, even if that wasn't specified in the original XML.

The QEMU driver *doesn't* set driver.type during postparse though; instead, it waits until domain startup time (or device attach time for hotplug), and sets the driver.type then. The result is that a parse-format round trip of the XML in the QEMU driver *doesn't* add in the <driver name='vfio'/>. This patch modifies the Xen code to behave similarly to the QEMU code - the PostParse just checks for a driver.type that isn't supported by the Xen driver, and any explicit setting to "xen" is deferred until domain runtime rather than during the postparse. This delayed setting of driver.type of course results in slightly different xml2xml parse-format results, so the unit test data is modified accordingly. Signed-off-by: Laine Stump <laine(a)redhat.com&gt; --- src/libxl/libxl_domain.c | 65 +++++++++++++++---- src/libxl/libxl_driver.c | 25 ++++--- tests/libxlxml2domconfigdata/moredevs-hvm.xml | 1 - tests/xlconfigdata/test-fullvirt-pci.xml | 2 - tests/xmconfigdata/test-pci-dev-syntax.xml | 2 - tests/xmconfigdata/test-pci-devs.xml | 2 - 6 files changed, 69 insertions(+), 28 deletions(-) diff --git a/src/libxl/libxl_domain.c b/src/libxl/libxl_domain.c index 22482adfa6..ecdf57e655 100644 --- a/src/libxl/libxl_domain.c +++ b/src/libxl/libxl_domain.c @@ -160,8 +160,15 @@ libxlDomainDeviceDefPostParse(virDomainDeviceDef *dev, if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS && hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI && - pcisrc->driver.type == VIR_DEVICE_HOSTDEV_PCI_DRIVER_TYPE_DEFAULT) - pcisrc->driver.type = VIR_DEVICE_HOSTDEV_PCI_DRIVER_TYPE_XEN; + pcisrc->driver.type != VIR_DEVICE_HOSTDEV_PCI_DRIVER_TYPE_DEFAULT && + pcisrc->driver.type != VIR_DEVICE_HOSTDEV_PCI_DRIVER_TYPE_XEN) { + + /* Xen only supports "Xen" style of hostdev, of course! */ + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("XEN does not support device assignment mode '%1$s'"), + virDeviceHostdevPCIDriverTypeToString(pcisrc->driver.type)); + return -1; + } } if (dev->type == VIR_DOMAIN_DEVICE_VIDEO) { @@ -986,18 +993,9 @@ libxlNetworkPrepareDevices(virDomainDef *def) if (actualType == VIR_DOMAIN_NET_TYPE_HOSTDEV && net->type == VIR_DOMAIN_NET_TYPE_NETWORK) { /* Each type='hostdev' network device must also have a - * corresponding entry in the hostdevs array. For netdevs - * that are hardcoded as type='hostdev', this is already - * done by the parser, but for those allocated from a - * network / determined at runtime, we need to do it - * separately. + * corresponding entry in the hostdevs array. */ virDomainHostdevDef *hostdev = virDomainNetGetActualHostdev(net); - virDomainHostdevSubsysPCI *pcisrc = &hostdev->source.subsys.u.pci; - - if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS && - hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI) - pcisrc->driver.type = VIR_DEVICE_HOSTDEV_PCI_DRIVER_TYPE_XEN; if (virDomainHostdevInsert(def, hostdev) < 0) return -1; @@ -1007,6 +1005,46 @@ libxlNetworkPrepareDevices(virDomainDef *def) return 0; } + +static int +libxlHostdevPrepareDevices(virDomainDef *def) +{ + size_t i; + + for (i = 0; i < def->nhostdevs; i++) { + virDomainHostdevDef *hostdev = def->hostdevs[i]; + virDomainHostdevSubsysPCI *pcisrc = &hostdev->source.subsys.u.pci; + + if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS && + hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI && + pcisrc->driver.type == VIR_DEVICE_HOSTDEV_PCI_DRIVER_TYPE_DEFAULT) { +